U.S Air Force Airman Alex McClendon, 633rd Aerospace Medicine Squadron bioenvironmental engineer technician, tests a water sample at Langley Air Force Base, Va., Feb. 9, 2016. Routine water samples are taken from various facilities across the base testing for chlorine, potential hydrogen and bacteriological matter in the water. (U.S. Air Force photo by Senior Airman Brittany E. N. Murphy)

U.S Air Force Airman Alex McClendon, 633rd Aerospace Medicine Squadron bioenvironmental engineer technician, tests a water sample for potential hydrogen at Langley Air Force Base, Va., Feb. 9, 2016. Bioenvironmental Airmen conduct air, water, noise and radiation sampling for numerous facilities around the base. (U.S. Air Force photo by Senior Airman Brittany E. N. Murphy)

M-50 gas masks prepare to be prepped for fit testing at the 633rd Aerospace Medicine Squadron bioenvironmental office at Langley Air Force Base, Va., Feb. 9, 2016. Bioenvironmental conduct gas mask fit tests for U.S. Service members, ensuring they have a tight seal in the event of chemical warfare in a deployed environment. (U.S. Air Force photo by Senior Airman Brittany E. N. Murphy)

U.S Air Force Airman Alex McClendon, 633rd Aerospace Medicine Squadron bioenvironmental engineer technician, dons a Mine Safety Appliances FireHawk mask at Langley Air Force Base, Va., Feb. 9, 2016. Bioenvironmental Airmen use these masks when going on supplied air to respond to an emergency, such as entering contaminated areas. (U.S. Air Force photo by Senior Airman Brittany E. N. Murphy)

U.S Air Force Airman Alex McClendon, 633rd Aerospace Medicine Squadron bioenvironmental engineer technician, adjusts his Mine Safety Appliances FireHawk mask at Langley Air Force Base, Va., Feb. 9, 2016. Bioenvironmental personnel perform gas mask and respirator fit tests with a Portacount Pro+, which reads the particle count inside the mask versus outside of it, to ensure a proper seal to protect U.S. Service members from potentially hazardous chemicals. (U.S. Air Force photo by Senior Airman Brittany E. N. Murphy)